Liquid laundry starch



United States Patent LIQUID LAUNDRY STARCH Allen R. Fuller, Decatur, Ill., assignor to A. E. Staley Manufacturing Company, Decatur, Ill., a corporation of Delaware No Drawing. Application March 23, 1954, Serial No. 418,245

4 Claims. (Cl. 106-213) This invention relates, generally, to improvements and innovations in liquid laundry starch compositions which are winterized and have prolonged shelf life, and which are characterized by their freedom from corrosive action on garments and fabrics in the presence of metal attachments such as metal zippers, buttons, hooks and ornaments.

The present application is a continuation-in-part of my copending application Serial No. 263,003 filed December 22, 1951.

Liquid laundry starches have become increasingly popular, particularly for home laundry use, since starch in this form obviates the need for preparing a starch dispersion each time starch is needed. It is, of course, well known that the ordinary starch dispersions prepared at home do not keep well and therefore it is the practice to prepare only enough for immediate needs and any extra is usually discarded. Not only is this practice wasteful of the starch, but in addition there is little uniformity in the starch dispersions prepared under home conditions.

By the designation liquid laundry starch as used herein and in the appended claims it is intended to designate a commercial product of high uniformity which is stable under ordinary conditions encountered in merchandising, storage and transit so as to have a prolonged and good shelf life whereby it will be and remain in excellent condition when it reaches the housewife for use by. her over a substantial period of time. An ordinary solution or dispersion of starch consisting only of starch and water will not meet these rigid conditions so as to constitute a liquid laundry starch within the above designation.

Numerous addition agents have from time to time been incorporated in liquid laundry starches with a view of making suitable products. In general, the prior art has suggested addition of various salts, particularly common salt or sodium chloride, to impart many of the desired properties. Major functions of these salts are to winterize, or impart resistance to cold, so that the product will resist freezing or other undesired change during shipment and during storage in unheated warehouses or storage rooms, and to prolong shelf life under normal conditions.

The Winterizing of the liquid laundry starch products is desirable, not only from a standpoint of providing resistance to freezing and cold, but also in inhibiting and preventing separation of the ingredients in the productif it is exposed to low temperatures. The liquid laundry starch products of this type tend, under low temperature conditions, to lose their original homogeneous character with the result that some of the ingredients may settle out or form layers. Once this occurs, it may not be possible to re-constitute the product to its original condition, even upon vigorous mixing or shaking.

While the electrolyte salts previously used may impart adequate resistance to these undesirable changes or developments in a liquid laundry starch product, a troublesome defect has been traced to the incorporation or presence of these strong electrolyte salts in liquid laundry Patented June 18, 1957 starch compositions. Thus, it was discovered in connection with the making of the present invention that when clothes or garments having metallic zippers, ornaments, fasteners, etc. are starched with a liquid laundry starch containing a strong electrolyte salt such as ordinary salt, as a Winterizing or stabilizing agent, the fabrics often become weakened, discolored and even completely eaten through. Originally, the cause of the damage was obscure but it was established that it was due to an electrochemical corrosive action which occurred, particularly during the conditioning, when the damp clothes were rolled up and metallic fasteners or ornaments were in intimate contact with the damp salt-containing starch compositions. The action of the strong acids generated was accentuated when brought into contact with a hot iron, resulting in the formation of many holes and scorching in the fabrics.

According to the present invention, it was discovered that the use of the strong electrolyte salts could be dispensed with and a satisfactory liquid laundry starch product obtained by using proper concentrations of a mixture of borax and sodium bicarbonate in the ratio of approximately two parts of borax to one of sodium bicarbonate, as the Winterizing agent. This Winterizing combination or mixture maybe used alone or in the presence of additional ingredients including urea, Calgon (sodium hexametaphosphate), sodium benzoate, sulfonated castor oil, soap, coloring materials, preservatives and perfumes.

Preferably, the mixture of borax and sodium bicarbonate is used in a concentration of from about 2.5 to 2.75% by weight of the product and the mixture is added after the starch has been cooked with the water. However, as disclosed in my aforementioned copending application Serial No. 263,003 the borax-bicarbonate mixture may be used in a concentration of from 2 to 4%.

Accordingly, the obiect of the invention is the provision of an improved liquid laundry starch product which is suitably winterized with a mixture containing approximately two parts of borax to one part of sodium bicarbonate, with or without additional Winterizing or stabilizing ingredients which do not lead to the production of corrosive acids, and which may include such materials as urea, Calgon, soap, sulfonated castor oil, sodium benzoate, preservatives, dyes and perfumes.

Certain other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.

For a more complete understanding of the nature and scope of the invention, reference may now be had to the following detailed description thereof wherein certain presently preferred formulations are set forth in the examples not only for the purpose of instructing those skilled in the art as to the manner in which the invention may be practiced but also to suggest to them other embodiments of a similar nature coming within the scope of the claims.

Various types of starch may be used in accordance with the present invention to prepare liquid laundry starch compositions. The starch may be obtained from corn, potatoes, rice, waxy maize, sorghum, and other sources. From all-round considerations, corn starch is preferable. While raw starch may be used satisfactorily, improved results may be obtained by using starch which has been suitably modified or converted by chemical or enzymatic action as is well known in the art. For example, hypochlorite oxidized starches and acid treated starches may be used to advantage. It has been found'that a satisfactory range for a starch concentration is from about 5 to 15% by weight.

' In general, the starch is added to the water with agitation along with such other ingredients'as sodium hexametaphosphate, sulfonated castor oil, soap and dyes if any of these materials are used. The starch water mixture is heated to boiling and then maintained just below boiling for a suitable period of time, e. g. to minutes. Thereafter, the cooked mixture is allowed to cool to about 140 F. and the mixture of borax and sodium bicarbonate is added along with any perfume that may be used and any preservative that may be added.

Reference may now be had to the following examples for more detailed information as to preferred and illustrative embodiments of the invention:

Example 1 Grams Water 1000 Starch 101 Calgon (sodium hexametaphosphate) 1.8 Borax 20 Sodium bicarbonate 10 Sulfonated castor oil 0.1 BMU (betamethyl umbelliferone) 0.1 Neutral soap (Ivory) 0.3 Dye (Monastral bl-ue BWD) 0.005 Perfume 0.125 Preservative (Mersolite phenyl mercuric acetate) 0.02

The starch is first added to the water at room temperature with efficient agitation so as to prepare a slurry. Then the Calgon, sulfonated castor oil, BMU, soap and dye are added to the starch slurry and the mixture is heated to boiling and maintained just below the boiling point for approximately 30 minutes. The heating is then discontinued and the temperature of the mixture allowed to drop to about 140 P. Then the balance of the ingredients in the above formulation is added to the cooked starch solution with the mixture being efliciently agitated during the addition. The resulting homogeneous product is allowed to cool to room temperature and is then ready to be packaged in pint or quart containers or other suitable sized containers as may be desired.

If desired, a portion of the water may be omitted until after the starch has first been cooked and the other ingredients added. When necessary, the finished product may be filtered through a screen (about mesh) before it is packaged so as to remove any solid materials that may be present.

Example 2 Grams Water 1000 Starch 80 Calgon (sodium hexametaphosphate 5 Urea 30 Borax 20 Sodium bicarbonate 10 Preservative (phenyl mercuric acetate) 0.02 Dye (Monastral blue BWD) 0.005

The foregoing ingredients may be mixed and processed in accordance with the procedure outlined above in connection with Example 1. That is, the starch, Calgon and dye may be first cooked together in the water and after cooling to 140 F., the mixture of borax and sodium bicarbonate together with the urea and the preservative will be blended in.

Example 3 Grams Water 1000 Starch Urea 20 Borax 20 Sodium bicarbonate 10 Sodium benzoate 10 Calgon (sodium hexametaphosphate) 2 Sulfonated castor oil 2 Preservative (phenyl mercuric acetate) 0.02 Dye (Monastral blue BWD) 0.00540 Example 4 Grams Water 1000 Starch Borax 20 Sodium bicarbonate 10 Sodium benzoate 10 Preservative (phenyl mercuric acetate) 0.02 Dye (Monastral blue BWD) 0.005-10 Perfume 0.125

Example 5 Grams Water 1000 Starch 70 Borax 20 Sodium bicarbonate 10 Preservative (phenyl mercuric acetate) 0.02 Dye (Monastral blue BWD) 0.00510 The formulations in Examples 3, 4 and 5 may be prepared in accordance with the procedure outlined in connection with Examples 1 and 2.

It will be noted that in the foregoing examples the starch concentrations range from 5.35 to 10.7% by weight of the compositions andthat the mixture of borax and sodium bicarbonate ranges in concentration from 2.57 to 2.72% by weight, i. e. from about 2.5 to 2.75%.

In Examples 1 and 5 the mixture of borax and sodium bicarbonate constitutes the sole Winterizing ingredient.

The use of Calgon or equivalent sequestering agent may be desirable where there is a need to inhibit the formation of objectionable precipitates, depending upon the water used. Thus, the use of Calgon or the equivalent material may in such instances prolong shelf life of the product.

The use of a fraction and up to 1% of sulfonated castor oil, or an equivalent substance, is also desirable in that it functions as a lubricant in ironing and also may contribute to shelf life.

The inclusion of a small amount of preservative material is desirable for prolonging shelf life. The particular preservative mentioned or others may be used. Suitable dyes and perfumes are added as desired.

Having fully described the invention, what is claimed as new is:

1. A liquid laundry starch consisting essentially of a cooked aqueous dispersion of starch containing from about 5 to 15% by weight of starch stabilized with from about 2 to 4% by weight of a mixture of borax and sodium bicarbonate wherein there are about two parts of borax to one part of sodium bicarbonate.

2. A liquid laundry starch consisting essentially of a cooked aqueous dispersion of starch containing from about 5 to 15% by weight of starch and an effective amount up to about 1% by weight of sodium hexametaphosphate, stabilized with about 2 to 4% by weight of a mixture of borax and sodium bicarbonate wherein there are about two parts of borax to one part of sodium bicarbonate.

3. The method of preparing a stabilized liquid laundry starch comprising heating an aqueous dispersion of starch containing from about 5 to 15 by weight of starch up to approximately boiling and maintaining said dispersion slightly below boiling for about 25 to 35 minutes, cooling the cooked dispersion to about F. and blending therewith about 2 to 4% by weight of a mixture of borax and sodium bicarbonate wherein there are about two parts of borax to one part of bicarbonate.

4. The method of preparing a stabilized liquid laundry starch comprising cooking an aqueous starch dispersion containing from about 5 to 15% by weight of starch and up to about 1% by weight of sodium hexametaphosphate slightly below the boiling point for about 30 minutes, cooling to about 140 F. and blending therewith about 2 to 4% by weight of a mixture of borax and sodium bicarbonate wherein there are about two parts of borax to one part of bicarbonate.

References Cited in the file of this'patent UNITED STATES PATENTS Mathias July 22, 1924 Hall Mar. 7, 1939 FOREIGN PATENTS Germany July 16, 1937 

2. A LIQUID LAUNDRY STARCH CONSISTING ESSENTIALLY OF A COOKED AQUEOUS DISPERSION OF STARCH CONTAINING FROM ABOUT 5 TO 15% BY WEIGHT OF STARCH OF AN EFFECTIVE AMOUNT UP TO ABOUT 1% BY WEIGHT OF SODIUM HEXAMETAPHOSPHATE, STABILIZED WITH ABOUT 2 TO 4% BY WEIGHT OFF A MIXTURE OF BORAX AND SODIUM BICARBONATE WHEREIN THERE ARE ABOUT TWO PARTS OF BORAX TO ONE PART OF SODIUM BICARBONATE. 